Windows/Mac/Linux: Opera's letting us have a look at how extensions will work in their browser with the Opera 11 Alpha. It's very Chrome-like and convenient, and the browser itself has picked up a few improvements in this version, too.

But first: the extensions. You grab them from Opera's gallery, which had about 16 examples up when this post was written. Want to contribute your own? Opera has posted its developer documentation, too. The extensions install on the spot from the download link, line up in the upper-right corner of your browser, get managed and uninstalled from a simple configuration page, and mostly work with the JavaScript and CSS of a page to enact changes—so, basically, they're very, very Chrome-like.

Outside of extensions, Opera is citing speed and performance improvements in this version, and we're eager to give that a test, based on previous surprises. There's also a better mail panel, tweaked bookmarks management, and more support for HTML5 web features.